Thumb tack



R O T N E V N July 24, 1928.

I H. C- KARST THUMB TACK Filed Jan. 16, 1928 Patented July 24, 1928 UNITED STATES PATENT OFFICE.

THUMB TACK.

Application filed January 16, 1928. Serial No. 247,247.

My invention relates to a new and useful thumb tack whereby objects may be fastened to a support without being pierced or otherwise damaged.

Ii My invention relates more particularly to a thumb tack of" this general character ada ted for firmly and detachably securing car s, Bristol board, drawing paper and similar objects to a drawing board, wall or 10 other support.

My invention further relates to a thumb tack which is adapted to be permanently engaged with a support if so desired, it being at the same time possible to employ a." said tack for fastening a variety of objects successively without the necessity of removing or disengaging said thumb tack from said support.

In thumb tacks known and used hereto= t fore, it has been the practice to provide a stampin or head member having a central prong W ich is adapted to'pass through the object to be supported and through the support. To avoid piercing the object being 2 secured by the prong of the thumb tack, resort was had to a thumb tack having an elongated head portion and having the prong thereof positioned at one extremity of said head portion, the frictional engagement of said head portion with object to be secured or its pressure against the support into which the prong of the thumb tack has been driven being relied upon to secure the object to the support. In all of these constructions it is necessary completely to disengage the thumb tack from the support when the object secured thereby is to be removed or replaced. Furthermore, the mere pressure of the head piece ofthe thumb tack on the object inserted between it and the support or its frictional engagement with such object as the case may be, have frequently been inadequate, resulting in slipping and displacement of the object being secured.

To overcome these disadvantages and at the same time to provide a thumb tack which can be successfully employed for firmly and detachably securing objects to a support withoutpiercing or ,in anyway damaging such objects I have provided a thumb tack consisting of an elongated head piece formed of spring metal and havinga central. depression therein, so that when pressure is applied to the central depressed spring portion oi said head piece one end thereof will snap upwardly thus permitting the insertion of an object thereunder, said end being adapted to be snapped back downwardly intoa tightly clamping position over said object, the other end of said head piece being provided with prongs for engaging a suitable support to which it is desired to secure said object.

My invention further consists of the various novel features hereinafter described and claimed.

In the accompanying drawings:

Figure 1, represents a perspective view of a thumb tack embodying my invention.

Figure 2, represents a section on line 2-2 of Figure 1.

Figure 3, represents a sectional view of my novel thumb tack in the process of application. V

Figure 4, represents a similar view show- ,ing my novel thumb tack in the engaging position.

Figure 5, represents a perspective view of a modified form of my invention.

Figure 6, represents a plan View of a fur-' ther modified form of my invention.

Figure 7, represents a side elevation of Figure 6. b

For the purpose of illustrating my invention I have shown in the accompanying drawings one form thereof which is at present preferred by me, since the same has been found in practice to give satisfactory and reliable results, although it is to be understood that the various instrumentalities of which my invention consists can be variously arranged and organized and that my invention is notlimited to the precise arrangement and organization of the instrumentalities as herein shown and described.

Referring to the'drawings, in which like reference characters indicate like parts. 1 designates a thumb tack embodying my invention comprising the body portion 2 formed of spring metal and having the peripheral prongs 3. The body portion 2 is composed of the slightly curved or convexed portions as 4 and 5 and is provided with the central recessed spring portion 6. The

prongs 3 are stamped from either'end of the body portion 2 as will be seen from Figs. 1 to 4 inclusive. 7 designates a suitable support such as a drawing board, wall or the like, on which it is desired to secure the sheet of paper, drawing card or other ob'ect 8. The operation of my novel thumb tac is as follows: The prongs 3 of the thumb tack 1, are driven intothe drawing board or other support Z by pressing on the portions 5 and 6 of the head or body portion 2 of the tack 1. The pressure exerted on the portions 5 and 6 to drive the prongs 3 into the support 7 causes the free end 4 to snap upwardly out of contact with the support 7, as is clearly shown in Fig. 3. This is due to the presence of the spring recessed portion 6, the'general curvature or warping of the body portion 2 and the springy character of the metal from which it is made. The edge of the paper card or other object 8 is then inserted under the raised portion 4 and the latter is then pressed downwardly over the edge of the object 8 whereupon,'due to the novel construction just recited it snaps downwardly into a tightly clamping position over the edge of the object 8 as is clearly seen in Fig. 4. It will be noted that the recessed spring portion 6 lies substantiall fiat on the surface of the support 7 while the free end 4 is in the raised position and thatsaid portion 6 occupies a raised or arched position when the portion 4 is in the lower clamping position (see Fig. 4), in which position the spring metal body portion 2 as a whole is so .warped or cramped as to exert considerable pressure on the object 8 clamped under the portion 4. To withdraw or remove the object 8 it is merely necessary to press downwardly on the raised or arched spring portion 6 (see Fig. 4) whereupon the clamping end 4 snaps upwardly into the raised position thus freeing the object 8 (see Fig. 3).

It will now be apparent that my novel thumb tack serves efliciently and tightly to clamp an object 8 to a support 7 without in any way piercing or damaging such object. Furthermore, when objects of uniform size are to be successively secured to a given support, .it will be entlrely unnecessary to disengagethe thumb tacks 1 from said support since it is only necessary to press on the recessed spring portion 6 to raise the clamping portion 4 and remove the object thus freed whereupon another object of substantially equal dimensions is positioned on the support 7 and the end portions 4 of the respective thumb tacks employed are pressed down into their clamping positions over the edges of said object as above explained. This not only eliminates the often rather irritating task of pulling out and driving in thumb tacks whenever it is desired to change or remove the drawing card or other object 8, but greatly increases the life of the drawing board or other support 7 (such as a wall or the like) since it reduces to a minimum the number of holes or punctures made in such support.

In Figure 5 I have shown a modified form of my invention wherein I provide the body portion 2 on its underside with the bottom lugs 9 intermediate the recessed portion 6 and the prongs 3, said lugs being intended to facilitate the upward and downward snapping of the clamping portion 4.

In Fig. 6 I have shown a further modified form of my invention wherein the body portion 2 of the thumb tack 1 is provided with the rounded corners 10 and wherein the prongs 3 are stamped out from either of the portions 4 and 5 as at 11, it being understood that the opening left by the stamping out of these prongs may be closed by swagin the metal on either side of said opening.

The operation of the devices illustrated in Figs. 5 to 7 inclusive is the same asthat set forth in connection with the other figures of the drawings and hence need not be described.-

By providing a plurality of prongs 3 the thumb-tack 1 is prevented from rotation and its engagement with the support 7 is further improved.

It will now be apparent that I have devised a novel thumb tackwhereby an object may be firmly and detachably secured to a support without being pierced by the prongs of said thumb tack and whereby an object thus secured may be withdrawn and replaced without the necessity of disengaging said thumb tack from said support, the working principle of-my invention being the provision of an arched, warped body portion pr head having a central spring recessed portion and provided at one end thereof with prongs for engaging a support, the other end of said body portion being free and adapted to snap upwardly away from said support when said spring recessed portion is in contact therewith and to be snapped downwardly into a tightly clamping position against support when the pressure on said recessed spring portion has been relieved. If desired, I'might provide the underside of the outer edge of the portion 4 (see Fig. 5) withthe teeth or serrations 12 for the purpose of more firmly gripping the object 8 bein secured by this modified form of thumb taci.

Similarly, I may provide the underside of the outer edge of the portion 4 (see Fig. 7) with the pendant flange 13 which serves to take up some of the room between the portion 4 and the board 7 more tightly to clamp the object 8 therebetween-as will be apparent. 1

- I am aware that the invention ma be embodied in other specific forms wit out departing from the irit or essential attributes thereof, and. therefore desire the present embodimentto be considered in all spring metal and h'avin res ects as illustrative and not restrictive, re erence being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is

1. In a device of the character stated, a

head piece formed of spring metal having a central, offset portion, one. end of said head piece being provided with prongs adapted to engage a support and the other end thereof being adapted to be snapped towards and into a clamping position against said support to secure an ob]ect thereto, and to be snapped away from said support by the exertion of pressure on said central, ofli'set portion to release said object.

2. In a device of the character stated, a generally elongated head piece formed of central, oflt'set spring portion, one end 0 said head piece being provided with prongs adapted. to engage a support and the other end thereof being adapted to be snapped towards and into a clamping position against said support to secure an object thereto, and to e snapped away from said support by the exertion of pressure on said central ofiset sprin portion to release said object. p

03. n a device of the character stated, a generally elongated, convex head piece ormed of spring metal and having a central, oflfset, spring portion, one end of said head iece being provided with prongs adapte to engage a support and the other end thereof being adapted to be snapped towards and into a clamping position against said support to secure an object thereto, and to be snapped away from said support the exertion of pressure on said central, 0 set spring ortion to release said object.

4., In a evice of the character stated, a generally elongated, convex head piece formed of spring metal and having a central, offset spring portion, one end of said head piece being provided with prongs adapted to engage a support and the other end thereof being adapted to be snapped towards and into a clamping position against said support to secure an object thereto, and to be snapped away from said support by the exertion of pressure on said centra,

offset, spring portion, to release said object snapped away from said support b the exertion of pressure on said central 0 set, spring portion, to release said object means mtermediate said offset portion and said prongs for spacing said head iece from said su port, and means on t e underside of t e outer edge of said free end for engaging the upper surface of said object.

6. In a device of the character stated, a

head piece formed of spring metal and having a central, ofiset spring ortion, one end of said head piece bein a apted to be sen cured to a support and t e other end thereof being adapted to be snapped towards and into a clamping position against said an port to secure an object thereto, and to sai object, by the exertion of pressure on said central, ofiset portion, and means for spacing said head p1ece from said support.

HOWARD C. KAB ST.

snapped away from said support to release o 

